Index: trunk/Ohana/src/opihi/dvo/dmagaves.c
===================================================================
--- trunk/Ohana/src/opihi/dvo/dmagaves.c	(revision 3462)
+++ trunk/Ohana/src/opihi/dvo/dmagaves.c	(revision 4420)
@@ -41,5 +41,8 @@
   if (!GetPhotcodeInfo (argv[1], &code[0], &mode[0])) return (FALSE);
   if (!GetPhotcodeInfo (argv[3], &code[1], &mode[1])) return (FALSE);
-  if ((param = GetAverageParam (argv[5])) == AVE_ZERO) return (FALSE);
+  if ((param = GetAverageParam (argv[5])) == AVE_ZERO) {
+    GetAverageParamHelp ();
+    return (FALSE);
+  }
   code[2] = GetPhotcodeEquivbyCode (code[0][0].code);
   mode[2] = mode[0];